Brisbane - Ana Ivanovic advanced to the Brisbane International semi-finals and a possible showdown against Justine Henin with a 6-4, 7-6 (6) win on Thursday over Anastasia Pavlyuchenkova.
The 2008 French Open champion, playing her first tournament since September, led by a set and 4-0 before her serve misfired and her unforced errors mounted.
Pavlyuchenkova, an 18-year-old Russian who is ranked No. 40, rallied to win six of the next seven games but was broken while serving for the set, a double-fault forcing the tiebreaker.
She raced to a 4-1 lead in the tiebreaker and had set point at 6-5, but committed errors on the next three points to surrender the match to Ivanovic.
Third-seeded Ivanovic, who had work through tough three-set matches in the earlier rounds, was relieved to finish her quarter-final off in two sets.
"I'm so happy I managed to stay calm in the tiebreaker," she said. "I'm thrilled to be through."
For Henin, the service problems and unforced errors she overcame on Wednesday to reach the quarter-finals were an important part of finding some rhythm in her comeback to the women's tour.
The seven-time Grand Slam singles champion dropped her opening service game in each set of a 6-4, 6-3 win over No. 132-ranked Sesil Karatantcheva.
She was to play seventh-seeded Melinda Czink on Thursday, with the winner meeting Ivanovic in the semis.
This is Henin's first official tournament in her comeback.
She retired in May 2008 when she held the No. 1 ranking, so is playing in Brisbane and Sydney on wild card entries ahead of the Australian Open, which starts Jan. 18.
The 27-year-old Henin announced her comeback in September, soon after fellow Belgian Kim Clijsters won the US Open only three tournaments into a comeback from retirement.
The Belgians could meet in the Brisbane final, with Clijsters playing a quarterfinal against Czech player Lucie Safarova on Thursday night.